Police is trying to arrest the man who captured the act.
The Patna Police has arrested a man after a video of him allegedly raping a woman had gone viral on social media.
The woman had gone to take bath in Ganga river in Barh area when the incident took place, said Rural Superintendent of Police Anand Kumar.
"We have arrested one man. Now we are trying to find the man, who captured the act. The victim did not approach us. The date of the incident has not been determined," Mr Kumar added.
This comes less than two weeks after the principal and clerk of a private school in Patna's Phulwari Sharif were arrested for allegedly raping a Class 5 student repeatedly in the school premises for over a period of nine months.